Inside this place, members of the 6th Division come to spar and/or to settle scores. The entire building has had to be reinforced with some Seki-Seki after the last time an errant Hado turned one of the walls and part of the ceiling to rubble. Either way, the place is rarely empty and it's not at all uncommon to see Division members flinging Kido at one another with lunatic abandon.
In other news, its durability makes it absolutely perfect for conducting any manner of sparring, even between multiple Captains.
